This evolutionary stage of our popular HD primary kit now consists of only two components (the photos show two cover plates, one of which is for the PV/ET3/PK XL1 models, the other for the XL2 models), thus considerably simplifying installation compared to the old version with loose sleeves and two cover plates. It is now also suitable for the clutch baskets of the XL2 versions. The kit does not fit the springless primary wheels of the 50cc models. Since these should also get a longer gear ratio when the engine capacity is increased, the upgrade kit can be mounted in a new primary reduction ratio without any problems.

In principle such an upgrade kit should be used in every engine, not only in very powerful engines. The enormous torque of today`s engines also requires the use of reinforced shock absorber springs. This prevents the too soft standard springs from going on block and the noses of the clutch linings from working into the basket.

Note: Depending on the manufacturer and tolerances of the primary used, it is possible that the CNC cover plate is rubbed on the bearing seat or its bracing of the crankshaft bearing.

Then either distance the primary via spacers (see `Accessories`) or grind a slight radius on the bearing seat of the engine housing.